Field of the Invention
The present disclosure relates to a charging member, and a process cartridge and an electrophotographic image forming apparatus (hereinafter referred to as an “electrophotographic apparatus”) each using the charging member.
Description of the Related Art
A process for charging the surface of an electrophotographic photosensitive member, hereinafter referred to as a “photosensitive member”, is a contact charging process. The contact charging process includes applying a voltage to a charging member disposed in contact with the photosensitive member, generating micro-discharge near a contact portion between the charging member and the photosensitive member, thereby charging the surface of the photosensitive member.
A charging member used in the contact charging process generally has a configuration including a conductive elastic layer from the viewpoint of sufficiently securing a contact portion between the charging member and the photosensitive member. However, the conductive elastic layer contains a low-molecular-weight component, and thus image defects may occur due to bleeding of the low-molecular-weight component on the surface of the charging member. Therefore, for the purpose of preventing the low-molecular-weight component from bleeding on the surface of the charging member, a surface layer may be provided on the conductive elastic layer.
Japanese Patent Laid-Open No. 2001-173641 discloses an electro-conductive roll provided with an electro-conductive roll substrate containing a resinous material; and an inorganic oxide film as a bleed-preventing layer, which is formed by a sol-gel method, and covers a surface of the electro-conductive roll substrate.
In recent years, an electrophotographic apparatus has been desired to be further improved in speed and durability with expansion of applications of the electrophotographic apparatus. In order to realize this, a charging member capable of stably charging a photosensitive member over a long period of time has been demanded.